Have

Squirrel Dealer

When Squirrel Dealer enters, ask a person outside the game "Do you like Squirrels?" If they do, create a 1/1 green Squirrel creature token.

Maelstrom Nexus

The first spell you cast each turn has cascade. (When you cast your first spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Proxy

Urza's Workshop

{T}: Add {C}.
Metalcraft — {T}: Add {C} for each Urza's land you control. Activate only if you control three or more artifacts.

Clever Combo

Search your library for a host card or a card with augment, reveal it, put it into your hand, then shuffle.

Spara's Headquarters

({T}: Add {G}, {W}, or {U}.)
Spara's Headquarters enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Multi-Headed

At the beginning of each end step, if you rolled a die this turn,
Augment {4}{G} ({4}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Steam-Powered

{5}:
Augment {4} ({4}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Flooded Strand

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Birds of Paradise

Voracious Vacuum

When this creature enters, put a +1/+1 counter on target creature.

Half-Squirrel, Half-

Whenever a nontoken creature enters,
Augment {G} ({G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Sensei's Divining Top

{1}: Look at the top three cards of your library, then put them back in any order.
{T}: Draw a card, then put Sensei's Divining Top on top of its owner's library.

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Reflecting Pool

{T}: Add one mana of any type that a land you control could produce.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Squirrel Farm

{1}{G}: Reveal a card in your hand, covering the artist credit. Target opponent guesses the artist. If they guess wrong, create a 1/1 green Squirrel creature token.

Marsh Flats

{T}, Pay 1 life, Sacrifice Marsh Flats: Search your library for a Plains or Swamp card, put it onto the battlefield, then shuffle.

Eager Beaver

When this creature enters, you may untap target permanent.

Getting

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Half-Kitten, Half-

Whenever you're dealt damage,
Augment {2}{W} ({2}{W}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Overgrown Tomb

({T}: Add {B} or {G}.)
As Overgrown Tomb enters, you may pay 2 life. If you don't, it enters tapped.

Raugrin Triome

({T}: Add {U}, {R}, or {W}.)
Raugrin Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Misty Rainforest

{T}, Pay 1 life, Sacrifice Misty Rainforest: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

Stinging Scorpion

When this creature enters, target creature an opponent controls gets -1/-1 until end of turn.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Half-Shark, Half-

At the beginning of your upkeep,
Augment {5}{U} ({5}{U}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Bumbling Pangolin

When this creature enters, you may destroy target artifact.

Disallow

Counter target spell, activated ability, or triggered ability. (Mana abilities can't be targeted.)

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Jace, the Mind Sculptor

+2: Look at the top card of target player's library. You may put that card on the bottom of that player's library.
0: Draw three cards, then put two cards from your hand on top of your library in any order.
−1: Return target creature to its owner's hand.
−12: Exile all cards from target player's library, then that player shuffles their hand into their library.

Maelstrom Archangel

Flying
Whenever Maelstrom Archangel deals combat damage to a player, you may cast a spell from your hand without paying its mana cost.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Indatha Triome

({T}: Add {W}, {B}, or {G}.)
Indatha Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
Raffine's Tower enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Adorable Kitten

When this creature enters, roll a six-sided die. You gain life equal to the result.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Surgeon General Commander

Whenever you augment, enchant, or mutate a creature you control, draw a card.
{T}: Add {W}, {U}, {B}, {R}, or {G}.

Really Epic Punch

Target creature you control gets +2/+2 if it's a host or has augment. Then it fights target creature you don't control.

Bat-

Flying
At the beginning of each end step, if an opponent lost 3 or more life this turn,
Augment {1}{B} ({1}{B}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Ninja

You may activate Ninja's augment ability any time you could cast an instant.
Whenever this creature deals combat damage to a player,
Augment {2}{B} ({2}{B}, Reveal this card from your hand: Combine it with target host. Augment only as—oh, never mind.)

Counterspell

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Success!

Target creature gets +2/+2 until end of turn. If it's a host or has augment, it gains lifelink until end of turn.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Angelic Rocket

Flying
When this creature enters, you may destroy target nonland permanent.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Dirty Rat

When this creature enters, target opponent discards a card.

Serpentine

Landfall — Whenever a land you control enters,
Augment {2}{G} ({2}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Gnome-Made Engine

When this creature enters, create a 1/1 colorless Gnome artifact creature token.

Wooded Foothills

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Scalding Tarn

{T}, Pay 1 life, Sacrifice Scalding Tarn: Search your library for an Island or Mountain card, put it onto the battlefield, then shuffle.

Verdant Command

Choose two —
• Target player creates two tapped 1/1 green Squirrel creature tokens.
• Counter target loyalty ability of a planeswalker.
• Exile target card from a graveyard.
• Target player gains 3 life.

Verdant Catacombs

{T}, Pay 1 life, Sacrifice Verdant Catacombs: Search your library for a Swamp or Forest card, put it onto the battlefield, then shuffle.

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Rhino-

Whenever this creature blocks,
Augment {3}{W} ({3}{W}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Mer Man

When this creature enters, you may draw a card.

Very Cryptic Command

Choose two —
• Switch target creature's power and toughness until end of turn.
• Target creature can't be blocked this turn.
• Draw a card. If that card's art is by Wayne England, you may reveal it and draw another card.
• Assemble a Contraption.

Monkey-

Whenever a nontoken creature you control dies,
Augment {2}{G} ({2}{G}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Breeding Pool

({T}: Add {G} or {U}.)
As Breeding Pool enters, you may pay 2 life. If you don't, it enters tapped.

Chitterspitter

At the beginning of your upkeep, you may sacrifice a token. If you do, put an acorn counter on Chitterspitter.
Squirrels you control get +1/+1 for each acorn counter on Chitterspitter.
{G}, {T}: Create a 1/1 green Squirrel creature token.

Winds of Abandon

Exile target creature you don't control. For each creature exiled this way, its controller searches their library for a basic land card. Those players put those cards onto the battlefield tapped, then shuffle.
Overload {4}{W}{W} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Xander's Lounge

({T}: Add {U}, {B}, or {R}.)
Xander's Lounge enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Big Boa Constrictor

When this creature enters, roll a six-sided die. Target opponent loses life equal to the result.

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Hammer of Purphoros

Creatures you control have haste.
{2}{R}, {T}, Sacrifice a land: Create a 3/3 colorless Golem enchantment artifact creature token.

Shaggy Camel

When this creature enters, creatures you control get +1/+1 until end of turn.

Tibalt's Trickery

Counter target spell. Choose 1, 2, or 3 at random. Its controller mills that many cards, then exiles cards from the top of their library until they exile a nonland card with a different name than that spell. They may cast that card without paying its mana cost. Then they put the exiled cards on the bottom of their library in a random order.

Arcane Signet

Humming-

Flying
Whenever you attack with two or more creatures,
Augment {3}{W} ({3}{W}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Earl of Squirrel

Squirrellink (Damage dealt by this creature also causes you to create that many 1/1 green Squirrel creature tokens.)
Creature tokens you control are Squirrels in addition to their other creature types.
Other Squirrels you control get +1/+1.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Nut Collector

At the beginning of your upkeep, you may create a 1/1 green Squirrel creature token.
Threshold — All Squirrels get +2/+2 as long as seven or more cards are in your graveyard.

Savai Triome

({T}: Add {R}, {W}, or {B}.)
Savai Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Polluted Delta

{T}, Pay 1 life, Sacrifice Polluted Delta: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Dr. Julius Jumblemorph

Dr. Julius Jumblemorph is every creature type (even if this card isn't on the battlefield).
Whenever a host you control enters, you may search your library and/or graveyard for a card with augment and combine it with that host. If you search your library this way, shuffle.

Animate Library

Enchant your library
Enchanted library is an artifact creature on the battlefield with power and toughness each equal to the number of cards in it. It's still a library.
If enchanted library would leave the battlefield, exile Animate Library instead.

Jace, Wielder of Mysteries

If you would draw a card while your library has no cards in it, you win the game instead.
+1: Target player mills two cards. Draw a card.
−8: Draw seven cards. Then if your library has no cards in it, you win the game.

Ziatora's Proving Ground

({T}: Add {B}, {R}, or {G}.)
Ziatora's Proving Ground enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Jetmir's Garden

({T}: Add {R}, {G}, or {W}.)
Jetmir's Garden enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Half-Orc, Half-

Trample
At the beginning of each end step, if an opponent was dealt damage this turn,
Augment {1}{R}{R} ({1}{R}{R}, Reveal this card from your hand: Combine it with target host. Augment only as a sorcery.)

Labro Bot

When this creature enters, return target host card or card with augment from your graveyard to your hand.

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Bloodstained Mire

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
Ketria Triome enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Who // What // When // Where // Why

Urza, Academy Headmaster

+1: Head to AskUrza.com and click +1.
−1: Head to AskUrza.com and click -1.
−6: Head to AskUrza.com and click -6.

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.